P-14: Monocentric islet autoantibody screening in young individuals with and without risk factors for type 1 diabetes
R Squintani, M Martino, M E Amodeo, F Silvestri, N Rapini, V Pampanini, A Deodati, P Ciampalini, C M Trovato, F Ferretti, A Diamanti, S Ceccarelli, G Bracaglia, O Porzio, S Cianfarani, R SchiaffiniAbstract
Introduction
Early detection of β cell-autoantibodies represents the strongest predictive indicator of the disease process in type 1 diabetes.
Objectives
We explored the prevalence of islet autoantibody positivity across different clinical subgroups.
Methods
At Bambino Gesù Children’s Hospital, 446 individuals were screened for islet autoantibodies (IAA, GADA, IA-2A and ZnT8A), with median age of 8.6 years (range 0.9–20.8). Since 2020, an islet autoantibody screening programme was offered to first-degree relatives of individuals with type 1 diabetes. Recently, screening was extended to children aged 0–10 years undergoing routine blood testing, as well as to patients with coeliac disease or autoimmune thyroiditis. Islet autoantibodies were measured using an enzyme-linked immunosorbent assay (ELISA), and positivity was confirmed on repeat testing. Participants were categorised according to the presence of autoimmune diseases and first-degree relative with type 1 diabetes.
Results
The prevalence of islet autoantibody positivity varied across clinical subgroups. Among patients with celiac disease (CD) (n=155), single autoantibody positivity was observed in 20% of individuals, while multiple autoantibody positivity was detected in 3%. Among those with autoimmune thyroiditis (AT) (n=21), 14% showed single autoantibody positivity and 24% had multiple autoantibodies. Among individuals with both autoimmune diseases (CD and AT) (n=11), 36% and 9% had single and multiple autoantibody positivity, respectively. Individuals without autoimmune diseases showed lower rates of single (7%) and multiple (2%) autoantibody positivity. The presence of a first-degree relative with type 1 diabetes did not modify autoantibody prevalence in any of the subgroups.
Conclusions
These findings support the importance of autoantibody screening, particularly in patients with autoimmune diseases and in first-degree relatives of affected individuals. Pre-existing autoimmunity was a stronger indicator of islet autoantibody presence than family history alone.